yo_marc

Hey all. How do the spring rates of 18/59 springs compare to aftermarket 2-door JK springs in the 2-2.5" range?

IE: Are 18/59's stiffer than Light Duty OME's, but 'about the same' as Heavy Duty OME's?

I'm assuming that 18/59's are a bit shorter and stiffer than something like your run of the mill single-rate 2.5" coils. But not sure.


Thanks!

JKred

On a 2 door you should run about 1.25" height increase in front, .75" rear, depending on the springs you had before.

The ride really won't be any different, barely noticeable. The spring generally isn't any stiffer, but longer.

JK Inspired

We went from 14/56 coils to 18/59 and shocks on Our 2 door and the ride difference is VERY NOTICEABLE with the height of the springs almost the SAME. ARB has an application guide that will be very informative and will answer your ??? If We were going to run 35s, probably would do the OME lights and MCE flatties, but We are doing 285/75s.

JK Inspired

In adding, I called around to the different manufacturers, and they are reluctant to give their rates out. I back-doored a few and know that TF is over 200 LB FT/inch, JKS at 140, OME heavy rear is 160, etc. JEEP will not disclose but believe they are somewhere around the 125-145 area. At $140 for new coils and rubi shocks, can't go wrong.

OrthoDoc

I went from 18/59's to AEV 2.5 in coil lift, and there was a dramatic difference in lift height as well as ride on my 2-door. The AEV coils are a good bit stiffer (this could also have to do with the Bilsteins). I gained about 1.5 inches in front, 1 inch in rear with the 18/59 from my original 14/56. I added another 2.5 inches in lift front and rear with the AEV lift from the 18/59's. My spring perch to frame measurement on the front is ~6.5 inches. It was at 4" with 18/59.

jeepchief

I went from 14/56's to 18/59's on my 2dr sport and gained 1.75" up front and 1.25" in the back. very noticeable in looks and ride quality. to me anyway. less dipping while braking, less rise while accelerating. Haven't really cornered to hard to notice if there was a difference. I'm sure when I get my bilsteins, things can only improve.

yo_marc

Guys, thank you! This has been very informative.

I thought for sure the 4-door springs would be heavier or stiffer than some of the popular aftermarket coils. It helps me to hear they're not.

The background - I'm running around in a primarily street driven lightweight 2-door. Came across some 18/59's locally for a price I couldn't pass up. I like to tinker, so I figured I'd toss them in to see what they were like... but was concerned about being over-sprung for the weight of my JK. If I heard that they were REALLY stiff compared to whats offered aftermarket, I'd probably bypass installing them altogether.

I've got a 14/15-55 combo under my JK now. Definitely has some dive, squat, and sway on the road. I'm always after better ride and bump handling... so I'm looking forward to trying these JKU springs out.

danompd

i went from 15/56 to the 18/59 and TF leveling kit (spacers) and 5100 bilsteins,gained 3.5 front and 2.25 rear looks and rides great. working on wheels and tires now

Invest2m4

It seems clear that changing the springs improves handling performance (I.e. cornering, dip, etc). I'm curious to hear what it does in terms of ride quality going down the road? Is it a stiffer/more jarring ride?

JK Inspired

It will be like any coil spring over time.